| Tag Offer Media Limited | Private company limited by shares | Live |
| Offside Media Limited | Private company limited by shares | Live Commenced dormancy on 30-Apr-2013 |
| Ombori Media Limited | Private company limited by shares | Live |
| Omni Media Limited | Private company limited by shares | Live |
| Omnii Media Limited | | Live |
| OmniWide Media Limited | | Live |
| OneCraze Media Limited | | Live |
| ONENESS MEDIA GROUP LIMITED | Private company limited by shares | Live |
| OneTake Media Limited | | Live |
| MEDIA ONLINE LIMITED | Private company limited by shares | Dissolved |
| CW ONLINE MEDIA LIMITED | Private company limited by shares | Dissolved |
| Online Media Limited | Private company limited by shares | Live |
| 404 ONLINE MEDIA LIMITED | Private company limited by shares | Live |
| ACC ONLINE MEDIA LIMITED | Private company limited by shares | Live |
| KR Online Media Limited | Private company limited by shares | Live |
| ONLY MID MEDIA LIMITED | | Live |
| Only Media Creation And Production Limited -The- | Private company limited by shares | Live |
| Onward Digital Media Limited | Private company limited by shares | Live |
| ONWARDS MEDIA GROUP (HK) LIMITED | Private company limited by shares | Live |
| OOHOO MEDIA LIMITED | Private company limited by shares | Live |
| OOVEE MEDIA LIMITED | Private company limited by shares | Live |
| OP-ED MEDIA LIMITED | Private company limited by shares | Live |
| OPEN CAR MEDIA LIMITED | Private company limited by shares | Live |
| Open Sky New Media Limited | | Live |
| Openload Media Asia Limited | Private company limited by shares | Live |
| OPENMIC DIGITAL MEDIA COMPANY LIMITED | Private company limited by shares | Live |
| CHINA MEDIA NETWORK OPERATE CO., LIMITED | Private company limited by shares | Live |
| HK PHOENIX NEW MEDIA OPERATION CO., LIMITED | Private company limited by shares | Dissolved |
| CHINA EDUCATION MEDIA OPERATION CENTER LIMITED | Private company limited by shares | Dissolved |
| Oppland Media Group Limited | Private company limited by shares | Live |
| Opportunities Media Limited | Private company limited by shares | Live |
| Opti Media Co., Limited | Private company limited by shares | Live |
| VOX OPTICAL MEDIA LIMITED | Private company limited by shares | Dissolved |
| ENCORE OPTICAL MEDIA LIMITED | Private company limited by shares | Dissolved |
| TIDETIME FUTURE OPTICAL MEDIA TECHNOLOGY LIMITED | Private company limited by shares | Live |
| OPTICAL MEDIA PRODUCTION LIMITED | Private company limited by shares | Dissolved |
| MSC OPTICAL MEDIA PRODUCTION LIMITED | Private company limited by shares | Dissolved |
| SENLAN OPTICAL MEDIA LIMITED | Private company limited by shares | Dissolved |
| STAR OPTICAL MEDIA LIMITED | Private company limited by shares | Live |
| Optimise Media (HK) Limited | Private company limited by shares | Live |
| Optimix Media Asia Limited | Private company limited by shares | Live |
| OPTIMUM MEDIA LIMITED | Private company limited by shares | Dissolved |
| OPTIMUM MEDIA LIMITED | | Live |
| Media Options Limited | Private company limited by shares | Live |
| OrangeCat Media Company Limited | Private company limited by shares | Live |
| Orant Media Limited | | Live |
| ORBIT MEDIA INTERNATIONAL CORPORATION LIMITED | Private company limited by shares | Live |
| ORCHID MEDIA LIMITED | Private company limited by shares | Dissolved |
| ORCHID MEDIA LIMITED | Private company limited by shares | Live |
| Oren Media & Technology Limited | Private company limited by shares | Live |
| Orient Media Company Limited | Private company limited by shares | Dissolved |
| ORIENT MEDIA COMPANY LIMITED | Private company limited by shares | Live |
| ORIENT MEDIA ADVERTISING LIMITED | Private company limited by shares | Dissolved |
| ORIENT PACIFIC MEDIA LIMITED | Private company limited by shares | Dissolved |
| ORIENTAL MEDIA CO. LIMITED | Private company limited by shares | Dissolved |
| Oriental Media Culture Limited | | Live |
| ORIENTAL VOGUE MEDIA GROUP LIMITED | Private company limited by shares | Dissolved |
| Bojie Oriental Media Holding Co. Limited | Private company limited by shares | Live Commenced dormancy on 06-Apr-2016 |
| ORIENTAL MEDIA INT'L HOLDING LIMITED | Private company limited by shares | Dissolved |
| ORIENTAL MEDIA INTERNATIONAL LIMITED | Private company limited by shares | Dissolved |
| ORIENTAL LUXURY MEDIA LIMITED | Private company limited by shares | Dissolved |
| Oriental Publishing & Media Co., Limited | Private company limited by shares | Dissolved |
| Oriental Media Solutions Company Limited | Private company limited by shares | Live |
| ORIENTAL SUNRISE MEDIA LIMITED | | Live |
| ORISTAR MEDIA TECHNOLOGY (HONGKONG) CO., LIMITED | Private company limited by shares | Live |
| Orris Media International Limited | Private company limited by shares | Live |
| O'RYAN MEDIA (HK) LIMITED | Private company limited by shares | Dissolved |
| OSSIMA MEDIA LIMITED | Private company limited by shares | Dissolved |
| OUTDOOR MEDIA LIMITED | Private company limited by shares | Dissolved |
| ASIA OUTDOOR MEDIA LIMITED | Private company limited by shares | Dissolved |
| CAMPUS OUTDOOR MEDIA LIMITED | Private company limited by shares | Dissolved |
| CHANNEL OUTDOOR MEDIA (HK) LIMITED | Private company limited by shares | Dissolved |
| OUTDOOR MEDIA HK CO., LIMITED | Private company limited by shares | Live |
| Asia Outdoor Media Co., Limited | | Live |
| TOM OUTDOOR MEDIA GROUP LIMITED | Private company limited by shares | Live |
| SPORTS AND OUTDOOR MEDIA (HK) LIMITED | Private company limited by shares | Dissolved |
| Outdoor Media Investments Limited | Private company limited by shares | Live |
| PANPACIFIC OUTDOOR MEDIA COMPANY LIMITED | Private company limited by shares | Live |
| SCMP Outdoor Media Limited | Private company limited by shares | Live |
| XINHUA OUTDOOR MEDIA COMPANY LIMITED | Private company limited by shares | Live |
| Outofthebox Media Limited | Private company limited by shares | Live |
| Media OutReach Limited | Private company limited by shares | Live |
| OVER MEDIA LIMITED | Private company limited by shares | Live |
| Overall Media Limited | Private company limited by shares | Dissolved |
| Overlab Media. Limited | | Live |
| OVERSEAS MEDIA LIMITED | Private company limited by shares | Live |
| Overseas Chinese Media Cooperation Organization Limited | Private company limited by shares | Live |
| OVERSEAS MEDIA GROUP LIMITED | Private company limited by shares | Live |
| OVERSEAS CHINESE MEDIA GROUP LIMITED | Private company limited by shares | Live |
| Lianpu Overseas Media Limited | | Live |
| OVERSEAS MEDIA SERVICE LIMITED | Private company limited by shares | Dissolved |
| OLIVIA AND OWEN MEDIA CO. LIMITED | Private company limited by shares | Live |
| OXYGEN MEDIA LIMITED | Private company limited by shares | Live |
| PACIFIC MEDIA LIMITED | Private company limited by shares | Dissolved |
| PACIFIC MEDIA LIMITED | Private company limited by shares | Live |
| MEDIA PACIFIC LIMITED | Private company limited by shares | Dissolved |
| MEDIA PACIFIC LIMITED | Private company limited by shares | Live |
| Asia & Pacific Media Limited | Private company limited by shares | Dissolved |
| ASIA PACIFIC MEDIA (HK) LIMITED | Private company limited by shares | Live |
| ASIA PACIFIC MEDIA HOLDING LIMITED | Private company limited by shares | Live |